There's a lot of Attenborough right now. No sign of him slowing down; the opposite if anything. Sir David Everywhere. He's over on Sky, doing the Galapagos in 3D (does anyone really sit at home wearing those glasses?). And here he is in Africa (BBC1). Actually the only time we see him is at the beginning, straddling the equator somewhere (as he is on Sky, in fact; perhaps he only operates at zero degrees latitude these days). When we go south to the Kalahari, we take only his voice with us. Well, he is 86, he doesn't need to be roaming around the desert.

The Kalahari, it turns out, is full of treasures: some familiar, others less so. Felines chase pretty deer things, always exciting in a slightly wrong way. Other creatures gather where there is water, which is not plentiful, obviously. It's dangerous, and hot, and dry. But there's the unexpected too, the extraordinary and the topsy-turvy. Birds eat crickets, right? Wrong. Here armoured ground crickets eat birds; or, if they can't find birds, they eat each other. Which is cleverer, a meerkat or a drongo? Duh! One runs a price comparison website, the other is a drongo … the meerkat, obviously. Wrong again: the ironically named drongo (a bird, incidentally) is so cunning it can trick Aleksandr Orlov out of his dinner through mimicry. Simples.

And the irony continues underground; beneath the baked earth are vast freshwater lakes, where blind golden catfish feel their way around. No one knows how deep they are, says Sir David. Well, why don't they lower a weight on a string to find out? Just a thought.

Has Attenborough's commentary become more grandfatherly, I wonder? Certainly he's not shy of slipping into a bit of anthropomorphism. "A girl can only put up with so much," he says about a female rhino being sex-pested by a horny young male at the water hole. And of a leopard stealing his mother's kill: "Like any teenager he thinks nothing of raiding her larder." I don't mind; it makes it warmer, friendlier, more like having a bedtime animal story read to you. Read by the nation's favourite granddad.

What I do mind is the incessant music, telling me how to feel. I don't need plinky plonky comedy music to tell me that young ostriches are humorous. Or a rousing orchestral crescendo to indicate the momentousness of a gathering of black rhinoceroses. Once you let it get to you it's impossible not to get crosser and crosser. Actually it's not quite incessant, and when it stops it's magical, because you can hear the sounds of what you're looking at. It's like being there. Sorry to bang on about it, I know I have before, but every time I do people get in touch to say they agree. How about some sort of red button option – press for the actual sound of the Kalahari? The music reaches a climax of absurdity when a young male giraffe shows up to challenge an old bull giraffe. Suddenly it sounds like the film score of a western. What is this, The Good, the Bad and the Spotty? Very High Noon? Pah!

The fight itself is extraordinary, though: the two giraffes neck-thwack the crap out of each other, an amazing spectacle and an amazing piece of filming. That's what this is all about. Attenborough's Galapagos show is actually more educational; he talks about evolution and Darwinism, all that. This looks better, but it's really wallpaper. The most glorious, highest-quality wallpaper, but still wallpaper.

The old giraffe wins the fight, sees off the young pretender, limps back into the desert. And perhaps there's just a hint of approval in Sir David's voice. He's not ready to step aside quite yet.

Secrets of a Good Marriage with Sharon Horgan (Channel 4) was more amusing than useful because the people the comedy writer and actor talks to are, well, freaks. There's a pair of sex maniacs. And another lady who has a lot of sex with just about everybody except her husband. And Steven the sexist, who explains to Sharon what he calls the "myth of equality" using the analogy of a pride of lions. "She goes and finds the food, brings it to him," he says. "His job is to protect the pride, so they make sure he is sorted and strong so he can fight another day. You don't look at the pride of lions and go: 'Ooh, that's a bit sexist.'"

Erm, because they're lions. Nor do you arrest an armoured ground cricket for murder and cannibalism. Drongo.